For many years the telephone system in general has known certain information about the phone from which a call has been made. For example, the telephone system has known what area code the call was placed from, the long distance carrier of the phone call, and even the approximate geographic location for a non-mobile phone based on the first six digits of the caller's number, based on the Local Exchange Routing Guide of Bellcore (LERG), at which the phone call was made, if it was a residential or non-mobile phone. However, in reality, the extent of information that has been able to be collected about a calling party by the telephone system is quite low. For example, consider a home in which two or more people reside. If a call is placed from that home there is no way of knowing, as the call is handled by the telephone system, who is making the call. The only thing the telephone system may know is the approximate geographic location of a non-mobile phone and the calling number. The call may even have been placed by a visitor to the home.
The examples of lack of knowledge about the calling party quickly expand when one considers phone calls originating from institutions (for example, hotels, hospitals, airports, offices, prisons, universities, etc.). Then consider mobile phones (Personal Communication System (PCS)/Service), air phones, maritime phones, and cellular phones, and it soon becomes apparent how little information is really known about a calling party. A public phone (such as a pay phone) in a lobby of an institution, provides little if any information about the calling party especially if the calling party is paying cash for the call.
Businesses have attempted to learn more about a calling party by asking questions of the calling party when their call is received. For example, a rental car company receives a call from a person wanting to rent a car. A live attendant for the rental car company will collect information about the caller by asking several questions. Consider that the caller is likely to have rented a car previously from the same company. There should be no need to have to re-ask all of the same questions every time the same caller wants to rent a car. Also consider the situation when the caller who is calling to rent a car, during the same call, requests information that is not known by the first attendant and the first attendant must transfer the call to another attendant such as a supervisor. Frequently in such situations it is necessary for the caller or the first attendant to have to repeat all or much of the caller's basic information to the second attendant. This unfortunate waste of time and resources goes on every day in calls occurring all over the world. The present invention provides a solution to this and related problems of telecommunications.
The telephone system has evolved to include limited standard identification information about the calling phone (calling number and/or ANI) and the phone that was called (dialed number). This information is primarily obtained from the telephone number from which the phone call was placed and the telephone number that was dialed by the caller. The telephone system has recognized these two numbers as basic information sources (for routing calls and for billing purposes for example) and has developed a system of standards for the data character fields these numbers are to fill. The following background information will better explain these standards of limited phone identification used today by the telephone system of the United States and as it applies to the international standards as well.
Automatic Number Identification
Automatic Number Identification (ANI) is a basic element of telephone calls transported throughout the public and private telephone networks. For the North America Numbering Plan (NANP), it is currently 10 digits long. ANI is used extensively for:
call routing PA1 call billing PA1 call tracking PA1 call identification. PA1 900 access code type calls (e.g., 1-900-WEATHER) PA1 500 access code type calls (e.g., 1-500 personal communications which currently can be billed to the caller) PA1 10XXX access code type calls (e.g., 10288 where the caller dials an access code to reach a carrier and then dials a number) PA1 1+ long distance number type calls per the caller's prescribed carrier PA1 411, 1-555-1212 and many other access codes, methods and applications PA1 collect calls PA1 1-500 (depending on features) PA1 1-700 (depending on features) PA1 1-800 (e.g., 1-800-SCHERER) PA1 other access methods, codes, and applications where the ANI is used, but the caller is not billed for the call (1-800-COLLECT, 1-800-CALL ATT, etc.). PA1 Intra-state PA1 Inter-state PA1 origination from a different country or island (e.g., calls from Canada) time zones PA1 mileage between calling parties and mileage bands. 1-800 access service was introduced by AT&T around 1967. From that time on, the caller's originating ANI became an integral part of the billing, routing, and call detail. 1-900, 411, and other pay-per-call numbers have also been around for 15 or more years and use the caller's originating ANI for part of the billing equation. PA1 1) 1-800 Access Type Service PA1 2) Integrated Services Digital Network (ISDN Service). PA1 a Service Switching Point (SSP) capability at a central office provides CCS7 trunk signaling and/or queries a database to determine call routing PA1 a Service Control Point (SCP) houses a database with the routing information used by network SSPs PA1 a Signaling Transfer Point (STP) provides routing capabilities for CCS7 messages between CCS7 nodes
Call Routing Based on ANI
Area Code Routing based on the calling phone number is a common feature found in most long distance telephone networks. Based on the calling party number (ANI) the call can be routed and/or receive special treatment by telephone switches, the phone network, and equipment. Some Interexchange Carriers (IXC's) (such as AT&T, MCI, Sprint, etc.) and Local Exchange Companies (LEC's) (such as Ameritech) provide many enhanced forms of call routing usually based on the first 3 or more ANI digit screening:
Call routing based on the first 3 ANI digits is usually referred to as Area Code Routing. For example, if the calling number ANI was 614-847-6161, then Area Code Routing would consider the "614" part of the ANI and route the Ohio originated call using the "614" as the broad geographic data element to start the routing routines and calculations, based on the routing rules and other factors (agents available, busies, lines available, time of day, day of week, percent allocation, and other factors).
Call Routing based on more than the first 3 ANI digits allows for more geographic precision. Most ANI's have a geographic relationship. Bell Core publishes a LERG (Local Exchange Routing Guide) that gives the approximate longitude and latitude for the area code/exchange (as well as other data contained in the LERG) represented by the first 6 digits of the ANI. For example, for the calling number 614-847-6161 the "614-847" component has the geographic representation of Ohio and the metropolitan area of North Columbus/Worthington. The Area-Code-Exchange (NPA-NXX) Routing ability gives even greater routing definition for the calling party (ANI). If a caller to an 800 number with an ANI of "614-847-6161" was in need of being connected to a towing service, then the geographically closest towing service might be identified to handle the towing job (at a shorter travel time and possible lower cost).
Call Routing can be based on the first 6 ANI digits or more. In fact, call routing can be extended to the first 7, 8, 9, or 10 digits to even focus on a single calling telephone number. For example, calls originating from "614-847-6161" could be assigned to a specific travel department within a company. The caller with that ANI could be routed by the telephone network to a certain group that always handles that travel department when that caller dials the local, 800, 500, or other number of a travel agency which routes calls using ANI. In this case, a specific ANI or set of ANI's is given a defined routing algorithm, or treatment, when recognized by a controlling network to route the call based on ANI or a group of ANI's.
Call Billing (Line ANI and Billing ANI)
ANI (as a term) is used, quite often interchangeably, for both the call originating billing number and/or the line number for the originating end of a call. For a location that has only one telephone line and one number (such as a residence with only one line), ANI usually refers to both the calling line and the billing number.
For a multi-line location (such as a business or residence with 2 or more lines), a PBX (Private Branch Exchange, a location's switch), or Centrex (where the local telephone company's switch or a separate switch acts as a PBX), the billing number or the lead number may be presented by the public telephone network as the ANI for the actual line used to place the call. For example, for a multi-line location such as a business, the public telephone network may present all the out-bound calls with the same ANI as the billing ANI even though multiple lines are in use, each with their own assigned line ANI and most of which are different than the billing ANI. The billing ANI is usually a good geographic representation of the non-mobile caller and usually represents the responsible (billing) party for the call (or one of them). However, in some cases, the billing ANI may not represent the actual ANI (or line number) of the call. In other cases, the billing ANI may not be presented and the line number ANI is presented instead. In any case, the line ANI or billing ANI never defines 100% of the time who is calling or why they are calling.
The ANI of the call may not even be a good geographic representation. For example, when a call is routed through a private network before it reaches the "Public Telephone Network", the ANI may have no relationship with the physical location or approximate identity of the caller. If the caller at one location calls through a tie line or on a "Private Network" to another location and then access the Public Network from the second location, the call will probably be identified by an ANI based on the point at which the call entered the Public Telephone Network of the second location. For example, if a caller in Columbus, Ohio accesses a switch in New York City through a private network and then accesses dial tone to reach the Public Telephone Network through the New York City switch, the ANI for the call will most likely be a New York City ANI and the bill will be based on the New York City ANI (distance, identification, location, bill to, etc.)
The caller's ANI (billing number and/or line number) is directly used for billing for calls dialed to:
The caller's ANI is indirectly (and sometimes directly) used as part of the billing equation for calls where the Dialed Number pays for the call:
For 1-800 access code calls, the caller's originating ANI is used to control some of the billing decisions--for example:
Call Tracking
ANI, along with Dialed Number including date and time, may be used as an approximation to track calls. However, if 2 callers dial from a PBX with a common billing ANI at the same time to the same multi-line location and both callers hang up at the same time, 2 call records will be created that look the same (even though there were 2 calls). Caller ANI, even with Dialed Number, date, time, and duration, do not provide exclusive call tracking, nor who was calling.
Most advanced PBX's, ACD's (Automated Call Distributors), network transferring features (such as AT&T's Transfer Connect), PBX call transferring, and other forms of call switching and call transferring--preserve and transfer the caller's ANI (if possible) in the transfer of a call. This is done to preserve this piece of network provided data to the next call location, in an attempt to better serve the caller, and to help identify the caller. ANI preservation and passing has been a feature of Computer-Technology Integration to manage calls.
Caller Identification
One of the most wide spread and well-known uses of the caller's ANI is Caller ID (Caller Identification). The concept of Caller ID is to pass on to the recipient of the call the ANI of the caller before the call is answered. ANI has been a key component of ISDN (Integrated Services Digital Network) defined by the CCITT in the 1970's. The caller's ANI has traveled the phone network since the 1970's, if not earlier, in the form of two products:
Many companies, businesses, and individuals use ISDN, digital access, and/or Caller ID to get the data elements of the call--one of which is caller ANI. Despite the benefits of ANI, caller ANI does not define the actual calling person. Even for a single line phone at a residence, ANI does not indicate which member of the family or a visitor is using the phone. Pay phones, businesses, and PBX's serve as gateways for an even larger number of individual people or equipment using a calling number's ANI. At best, caller ANI provides an approximation to the geographic location and an educated guess as to who may be calling. It does not indicate why the caller is calling.
The ANI of the caller is preserved and passed on as the call passes through the Public Telephone Network (and usually the Private Telephone Network, if possible). For example, the caller ANI may traverse through the LEC, IXC, CAP (Competitive Access Provider), PBX, ACD, Agent and so forth, so the final recipient receives the caller's ANI (i.e., caller ID).
Dialed Number
Dialed Number is the number that the caller dialed. Dialed Number, like ANI, must comply with the North America Numbering Plan (NANP) and the CCITT International Standards if the call is to originate and use the public switched telephone network of the U.S.A., Canada, North America (NANP) and international locations. Examples are:
______________________________________ 847-6161 7 digit dialing within the Local Access and Transport Area (LATA) where the area code is assumed to be the same as the local area code (i.e.: 614). With multiple area codes for the same LATA coming into existence, 7 digit dialing will be phased out in some areas to 10 digit dialing. 809-776-8500 These are examples of 10 digit dialing geographic 614-847-6161 numbers. The 809-776 indicates a phone number in St. Thomas, a U.S. Virgin Island. 1-800-356-6161 These are all examples of non-geographic routing 1-900-932-8437 numbers where the carrier and/or telephone network 1-500-422-7537 that has handled the call checks a database for the 1-700-328-5000 designated termination and associated routing. 911 These are examples of local special purpose Dialed 411 Numbers that again have specific routing and "0" geographic assumptions. 011-44 International Dialed Numbers that start with 011-72 international access, country code, and then the number (city, line, etc.) in the designated ______________________________________ country.
For North America and the countries (including the U.S.A.) which are using the NANP, the public switched telephone network requires the Dialed Number to conform to the NANP. The Dialed Number is passed on to each successive party of the transport of the call (LEC-IXC-LEC-PBX-ACD- etc.) so the call can go through the telephone network being routed to the destination and for call accounting purposes.
Dialed Number Identification Service
The Dialed Number Identification Service (DNIS) uses a shortened presentation form of the Dialed Number. When the incoming call is terminated on digital access (and other forms of special access), the transport provider will usually offer DNIS to help identify what number was dialed for an incoming call to the target telephone equipment and location. If the Dialed Number was, for example, 1-800-356-6161, then 6161 may be sent with the call presentation to reflect the 10 digit number dialed to give special treatment, routing, and information for the incoming call. The DNIS assigned could be from 1 to 10 digits or more (but usually not more than 10) and does not have to be the same as, or part of, the Dialed Number. In the above example, for the 800 number 1-800-356-6161, the DNIS could be "100" or "2" or the number itself.
A common use of DNIS, besides representing the Dialed Number, is to aid in routing the calls within the telephone equipment so multiple different Dialed Numbers can share a common access trunk group and a common routing and still receive selective routing and unique Audiotext greetings and selective handling. For example, within a business one 1-800 number may route to sales while a different 1-800 number for the same company routes to customer service, but calls to both numbers share the same or parts of the same trunk group to improve network, access, switch and telephone equipment utilization.
Dialed Number Routing
For the traditional geographic Dialed Number 411, 911, 614-847-6161, the public switched network will attempt to deliver the call to a primary location, and if the local phone company and/or the IXC offers advanced features (Call Forward on Busy, Call Forwarding, Call Forward on Ring No Answer, and other possible static and dynamic delivery options), the call can have special "pre-designated routings" that are mostly static in nature.
For non-geographic Dialed Numbers, such as 1-800, 1-900, 1-500 (PCS Follow Me), and other non-geographic Dialed Numbers, the routing is controlled by the local access provider's (LEC) accessing local databases to hand the call to the appropriate IXC (interexchange carrier) for providing inter-LATA (and intra-LATA) services and network routing and utilizes the traditional public telephone network supplied ANI plus Dialed Number(s) as some of the key data elements.
In both cases (geographic and non-geographic Dialed Numbers), the telephone network currently uses the public network supplied ANI and/or Dialed Number to determine call routing and special call treatment. Up until now, both the ANI and Dialed Numbers were fixed or static in nature, and are located in predesignated fields of the actual call data.
The USA Network and Many International Telephone Networks Support CCS7 Signaling
A CCS7 (Common Channel Signaling 7) network consists of nodes called Signaling Points (SPs). Unique point codes for each network SP serve as the address for message distribution. A typical CCS7 network (as referenced in FIG. 6 herein), has three key nodes:
The North American network will be based on the basic "Mesh" structure. This structure is sometimes referred to as the "Quad" structure.
The hub of the network will be STP pairs. These are two separate STP nodes operating together in a logical arrangement for redundancy.
The Signaling Links can be categorized into several types depending on the functions being performed. However, regardless of the function being performed, all Signaling Links operate in the same manner and have the same technical requirements.
A-Links (Access Links) are used to allow SSPs, SCPs and SPs to connect STP nodes.
B-Links (Bridge Links) are used to join mated STP pairs to other mated STP pairs.
These Links form the Quad structure, which will provide complete STP redundancy.
C-Links (Cross Links) are used to interconnect two STP nodes, in order to create an STP pair.
D-Links (Diagonal Links) interconnect primary and secondary Signal Transfer Point pairs. They provide communication between pairs and serve as an alternate routing path.
A two level hierarchy in an extension of the basic mesh structure.
Some networks, typically those with high levels of sub-network traffic volume, may require another level of STP pairs. This Primary level of the STP architecture would also be a convenient place to bridge signaling boundaries (i.e. from one operating region to another). Most CCS7 nodes will be connected to the network at Secondary level STP pairs, except SCPs may be connected at the Primary level.
D-Links (Diagonal Links) are used to form connections between Secondary level mated STP pairs and Primary level mated STP pairs. This forms a Quad structure as well.
Private Dialing Plans
AT&T in 1985 introduced its Software Defined Network ("SDN"), MCI offers Virtual Private Network ("VPN") and others offer private dialing plans (e.g., switch to switch) that may not conform to the public network. "On Net", a Private Virtual Network term, represents a dialing plan that may or may not conform to the public switched network (NANP). These private telephone networks are preprogrammed to receive calls over dedicated and special access and to look for the unique "Dialed Numbers" that can even look like public Dialed Numbers. The private numbers are translated and routed differently (or can be routed the same) as the public network. For example, dialing 1-614-847-6161 on a private telephone network could ring to a phone in New York City (or anywhere) instead of the expected geographic location of the Columbus area in Ohio.